The present invention is directed to a method for calculating spiral swath paths. More specifically, the present invention is directed to a method for calculating spiral swath paths in an area with irregular boundaries and providing automatic guidance of a vehicle along the calculated spiral swath paths.
A path planner may be used to determine one or more path plans for an agricultural vehicle to cover a work area. The work area may represent a field for growing a crop of other vegetation. The vehicle may need to traverse the entire work area or a portion thereof to plant a crop (or precursor thereto), to treat a crop (or precursor thereto), to harvest a crop, or to perform another task associated with the crop of vegetation, for example.
Agricultural vehicles commonly use manual or automatic guidance systems based on satellite positioning system such as global positioning (GPS). These systems typically allow the operator to record a base path of the vehicle and then automatically generate additional swaths parallel to this recorded swath. Often times straight-line guidance is used, or equally spaced curves along the field boundaries or constant elevation lines through the field.
Another common practice in farming is to drive a vehicle along the boundary, then as the vehicle approaches the point at which it entered the field, the vehicle is directed inward to position the vehicle parallel to the first swath path, minimizing any “skip” or “gaps” or in addition, any overlap as practical. The term skip or gaps, as used in this application, is any area left between swath paths. Skip is essentially any area that is not traversed by the vehicle and its associated implement and is therefore not included in the work area. Overlap, as used in this application, is any area or portion thereof that is covered by more than one swath path. Overlap is an area that the vehicle and its associated implement have been driven over repeatedly.
Therefore it would be a great advantage to provide a method for creating spiral swath patterns for use by a vehicle navigation system that streamlines data storage requirements to reduce demands on the storage and computational elements of the navigation system thereby reducing hardware expense of the vehicle guidance system. Further advantages would be realized if the method and apparatus for creating spiral swath patterns for use by a vehicle navigation system was capable of storing path positional data for future use, so that valuable time and energy is saved by eliminating the requirement to create a new baseline swath or provide a boundary before each use of the method. Still further advantages would be realized if the method recognized vehicle/implement limitations in following a defined path and adjusted such paths accordingly. These and other advantages are provided by the method and vehicle guidance system described below.